DESCRIPTION (Applicant's Abstract): The goal of this proposal is to establish reporter gene assays that utilize human skin equivalent cultures for testing the irritancy potential of chemical compounds. The assays will utilize a new and proprietary human skin cell line called NIKS (normal immortalized keratinocytes). NIKS cells can establish fully differentiated organotypic cultures of human skin. In contrast to primary keratinocytes, the immortalized NIKS cells can be used to generate genetically altered cell lines for simpler and faster read-outs of skin irritation. Human skin equivalent assays are the best alternative to animal testing for evaluating the irritation of chemical compounds on human skin. Such tests are needed to prevent the inclusion of irritating ingredients in consumer products, cosmetics, or topically applied pharmaceuticals. The investigators will generate a reporter gene using regulatory elements of a known irritant responsive gene, IL-18, to demonstrate the utility of reporter gene assays in NIKS cells. They also propose to use gene expression profiling to identify a panel of genes whose expression is altered in response to skin irritants. This gene expression information will be used in Phase II to guide the engineering of additional NIKS irritancy reporter cell lines and skin irritancy expression arrays. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE